Set 1

When this button is clicked, prompt for a todo, create the list item, then add it to the list:

Pick up dry cleaning

Set 2

When this button is clicked, prompt for an image source, width, and height.
Create an <img>, set the respective attributes, and put it in this box:

Set 3

This paragraph is currently not bold. But there's a class .bold
set up in the CSS. Add that class to this paragraph when this button below is clicked.
Need something more ambitious? Make clicking toggle the .bold class.